2021 Quetelet Seminar


Invisibilities and Uncertainties
in Population Sciences

27-29 October 2021, Teams


Although information on individuals has never been so abundant, particularly through administrative databases (registers, censuses, surveys) or private databases (tracking of individuals on the internet or by telephone networks), many populations are partially, or sometimes completely, unaffected by observations and measurements, whether voluntarily or not. A distinction should be made between invisibility and statistical uncertainty. Invisibility concerns categories of persons and/or events that are not or no longer measured or are differently measured. Statistical uncertainty is the lack or absence of data concerning marginal populations and events are those that are rare and difficult to enumerate quantitatively. These different situations lead de facto to invisibility or statistical uncertainty.

Invisibility often stems from the absence or loss of legal and administrative recognition. It can be both the consequence, and conversely, the driving force behind a process of social exclusion and involuntary marginalisation. This is the case, for example, of the homeless, and of people in an irregular situation regarding territory. Invisibility can also be the result of a voluntary choice by those who fear being stigmatised or who wish to be on the margins of society in order to escape certain lifestyles, or avoid information being collected about them that they consider intrusive. These invisibilities, whether suffered or deliberately maintained, constitute forms of ruptures between the individual and society, through lack of consideration or recognition, through mistrust, or because of a void that the administrative apparatus is unable to fill.

Invisibility can also arise coincidentally, without necessarily reflecting marginalization. For example, the usual place of residence does not always correspond to the "legal" place of residence. This is particularly the case for students or workers who live in one place (alone, as a couple, in a shared flat, etc.) while remaining legally domiciled and registered in another (at their parents’, for instance). This generates a difficult census/observation of these individuals and/or double counting. This statistical invisibility may also concern certain lifestyles, at first out of the norm, but more frequent in a context of changing family and conjugal life courses. These examples are indicative of the growing diversity of lifestyles and their rapid evolution (same-sex partners, single parental adoptions, non-marital cohabitation, shared residence of children following a parental separation, etc.). They arouse the interest of social science researchers, but require constant adaptation of the data collection tools to efficiently consider "new" phenomena and new population categories.

Similarly, official statistics, because of a certain inertia and because the measurement tools are not always adapted, often have difficulty transcribing the brutal changes that occur at the macro-social level, during economic, political or health crises, for example. The current health crisis has highlighted the problems of defining, measuring and comparing indicators.

At the same time, situations associated with past and/or present taboos are often subject to significant statistical underestimations. For example, questions about gender identities and sexual orientations remain minimal in the statistical space. Confronted with the heteronormativity of current statistics and of the whole society, lesbian, gay, bisexual, queer or transgender populations are likely to conceal their family or personal situation to escape social stigma, or because individuals do not recognize themselves in the proposed statistical categories. Administrative and statistical sources may elude some other sensitive topics because of the social and emotional weight they carry. Sexual and domestic violence is one example. Fear of reprisals, judgements and incomprehension are all arguments that may hold some victims back from reporting assaults or daily abuse. Finally, the social, religious and cultural history of a society leaves its mark on current reluctance to discuss delicate subjects, such as suicide, euthanasia or abortion. Because they trigger social condemnation and virulent debate, those topics are particularly difficult to study and to grasp without some form of bias or underestimation in traditional statistics, including in specific surveys on the subject.

The 2021 Quetelet Seminar proposes to examine not only these invisible populations and the uncertainty of events, but also the shortcomings of observation tools and how to statistically apprehend them. It seeks a better understanding of the determinants and effects of the process of statistical invisibility. Finally, it aims at highlighting the limits of current statistics in a context of multiple changes in our modern society.

We invite proposals that:

  • Have a conceptual and/or methodological scope, such as:
    • Questioning the concept of invisibility;
    • Estimating the quality of existing statistical data and their possible biases: non-responses or omissions - more or less voluntary on the part of respondents - and problems of representativeness;
    • Proposing unconventional approaches for the estimation of invisible populations, be it surveys or specific exploitations of administrative data, or approaches combining quantitative and qualitative aspects;
    • Recommending solutions to increase the statistical visibility of these populations or certain phenomena.
  • Focus on specific populations:

    • Refugees, illegal or undocumented migrants, homeless, mobile (or nomadic) populations, street children, student populations...
    • Analyses of the socio-economic consequences of this lack of visibility for the populations concerned but also for the society and local authorities in which they live.
  • Address specific phenomena, such as:

    • Family transitions and new household configurations;
    • Yesterday’s and today’s taboos: gender and sexuality, crime, violent deaths, abortion and reproductive health, perinatal deaths…;
    • Administrative blurring about housing, migration, family support...;
  • Examine the ethical and political issues of invisibility and the will to make visible.
  • Focus on the health and social crisis related to the COVID-19 epidemic and in particular:
    • On methodological and data collection issues
    • On its consequences with regard to certain low-visibility populations


Instructions for submission

  • Register at easychair
  • Click on « new submission »
  • Add the author’s or authors’ name(s), in the right order. Do not forget to add yourself as an author and to indicate the contact author.
  • Fill in the « Title and abstract » form, with a short abstract (250 words max.), in French or English. Abstracts are required to respect the following format :
    • General context
    • Objective
    • Methods
    • Results or expected results
    • Conclusion and/or (expected) contribution
  • Fill in the « Key-words » form (2 to 5 key-words)
  • Optional at this stage: upload the article or long abstract (only PDF version will be accepted, 4 pages min.)


Upcoming schedule

  • Deadline for proposal submission: May 8, 2021
  • Notification of acceptance/refusal to authors: mid-June 2021
  • Opening of authors' registrations: early September, 2021
  • Deadline for author registration: October 1, 2021
  • Conference Date: October 27-29, 2021



  • Free inscription 
  • The conference languages are English and French. However, all slides are requested to be in English even if the oral presentation is in French.
  • Conference format: visio, Teams.
  • Submission website: easychair
  • Contact : chairequetelet@uclouvain.be